312 



THE OXFORD OOLITE PERIOD. 



CHAP. 



plesiosaurus of the middle and upper oolites, while in the lias these 

 bones are always largely separated in the middle. In this our 

 plesiosaurs make some approach to the pavement-like structure in 

 the ichthyosaurs. There is a mark for a third smaller bone to be 

 in contact with the femur. 



No paddle has been found complete, or approaching to that 

 condition in the Oxford district ; but the bones rearranged appear 

 to give a total length, if complete, of about 30 or 36 inches to this 

 limb. 



Counting 96 vertebrao at i'6 inches, and the head, which cannot 



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Diagram CXV11. Paddle of Plesiosaurus Oxoniensis. Scale, one-tenth of nature. 



have been large, at 15 inches, we have, allowing for cartilage, 

 15 feet for the length of the animal, equal to five times the length 

 of the hinder paddle, and fifteen times the length of the 

 femur. 



Taking the length of the femur equal to 100 inches, the breadth 

 is 58, the whole paddle 277. 



